package com.hmdp.service.impl;

import cn.hutool.core.bean.BeanUtil;
import cn.hutool.json.JSONUtil;
import com.hmdp.dto.Result;
import com.hmdp.entity.VoucherOrder;
import com.hmdp.mapper.VoucherOrderMapper;
import com.hmdp.service.ISeckillVoucherService;
import com.hmdp.service.IVoucherOrderService;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.hmdp.utils.RedisIdWorker;
import com.hmdp.utils.UserHolder;
import lombok.extern.slf4j.Slf4j;
import org.redisson.api.RLock;
import org.redisson.api.RedissonClient;
import org.springframework.amqp.core.Message;
import org.springframework.amqp.rabbit.annotation.RabbitListener;
import org.springframework.amqp.rabbit.core.RabbitTemplate;
import org.springframework.aop.framework.AopContext;
import org.springframework.core.io.ClassPathResource;
import org.springframework.data.redis.connection.stream.*;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.data.redis.core.script.DefaultRedisScript;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;
import org.springframework.web.bind.annotation.RequestParam;

import javax.annotation.PostConstruct;
import javax.annotation.Resource;
import java.time.Duration;
import java.util.Collections;
import java.util.List;
import java.util.Map;
import java.util.concurrent.ArrayBlockingQueue;
import java.util.concurrent.BlockingQueue;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;


@Slf4j
@Service
public class VoucherOrderServiceImpl extends ServiceImpl<VoucherOrderMapper, VoucherOrder> implements IVoucherOrderService {

    @Resource
    private RabbitTemplate rabbitTemplate;

    @Resource
    private ISeckillVoucherService seckillVoucherService;

    @Resource
    private RedisIdWorker redisIdWorker;

    @Resource
    private StringRedisTemplate stringRedisTemplate;

    @Resource
    private RedissonClient redissonClient;

    private static final DefaultRedisScript<Long> SECKILL_SCRIPT;
    static {
        SECKILL_SCRIPT = new DefaultRedisScript();
        SECKILL_SCRIPT.setLocation(new ClassPathResource("seckill.lua"));
        SECKILL_SCRIPT.setResultType(Long.class);
    }
    //阻塞队列
    //线程任务 --线程池
    private static  final ExecutorService SECKILL_ORDER_EXECUTOR = Executors.newSingleThreadExecutor();
/*
    @PostConstruct //spring容器初始化的时候执行该方法。
    private void init(){
        SECKILL_ORDER_EXECUTOR.submit(new VoucherOrderHandler());
    }

    private class VoucherOrderHandler implements Runnable{
        //消息队列
        @Override
        public void run() {
            while (true) {
                try {
                    // 1.获取消息队列中的订单信息 XREADGROUP GROUP g1 c1 COUNT 1 BLOCK 2000 STREAMS s1 >
                    List<MapRecord<String, Object, Object>> list = stringRedisTemplate.opsForStream().read(
                            Consumer.from("g1", "c1"),
                            StreamReadOptions.empty().count(1).block(Duration.ofSeconds(2)),
                            StreamOffset.create("stream.order", ReadOffset.lastConsumed())
                    );
                    // 2.判断订单信息是否为空
                    if (list == null || list.isEmpty()) {
                        // 如果为null，说明没有消息，继续下一次循环
                        continue;
                    }

                    // 解析数据
                    MapRecord<String, Object, Object> record = list.get(0);
                    Map<Object, Object> value = record.getValue();
                    VoucherOrder voucherOrder = BeanUtil.fillBeanWithMap
                            (value, new VoucherOrder(), true);

                    // 3.创建订单
                    handlerVoucherOrder(voucherOrder);

                    // 4.确认消息 XACK
                    stringRedisTemplate.opsForStream().acknowledge
                            ("s1", "g1", record.getId());

                } catch (Exception e) {
                    log.error("处理订单异常", e);
                    handlePendingList();
                }
            }
        }
    }*/

    private void handlePendingList() {
        while (true) {
            try {
                // 1.获取pending-list中的订单信息 XREADGROUP GROUP g1 c1 COUNT 1 BLOCK 2000 STREAMS s1 0
                List<MapRecord<String, Object, Object>> list = stringRedisTemplate.opsForStream().read(
                        Consumer.from("g1", "c1"),
                        StreamReadOptions.empty().count(1),
                        StreamOffset.create("stream.order", ReadOffset.from("0"))
                );
                // 2.判断订单信息是否为空
                if (list == null || list.isEmpty()) {
                    // 如果为null，说明没有异常消息，结束循环
                    break;
                }
                // 解析数据
                MapRecord<String, Object, Object> record = list.get(0);
                Map<Object, Object> value = record.getValue();
                VoucherOrder voucherOrder = BeanUtil.fillBeanWithMap(value, new VoucherOrder(), true);
                // 3.创建订单
                handlerVoucherOrder(voucherOrder);
                // 4.确认消息 XACK
                stringRedisTemplate.opsForStream().acknowledge("s1", "g1", record.getId());
            } catch (Exception e) {
                log.error("处理订单异常", e);
            }
        }
    }



    /**
     * 取阻塞队列中的消息 --进行操作
     */
/*
    private BlockingQueue<VoucherOrder> orderTasks= new ArrayBlockingQueue<>(1024*1024);

    private class VoucherOrderHandler implements Runnable{

        @Override
        public void run() {
            while (true){

                try {//获取队列中订单信息
                    VoucherOrder voucherOrder = orderTasks.take();
                    //创建订单
                    handlerVoucherOrder(voucherOrder);
                } catch (InterruptedException e) {
                    log.error("异常：" +e);
                }
            }
        }
    }*/

    private IVoucherOrderService proxy;

    /**
     * stream消息队列 --优化异步秒杀
     * @param voucherId
     * @return
     */
/*
    @Override
    public Result seckillVoucher(Long voucherId) {
        //1、调用lua脚本
        Long userId = UserHolder.getUser().getId();
        //订单id
        long orderId = redisIdWorker.nextId("order");
        Long result = stringRedisTemplate.execute(SECKILL_SCRIPT
                , Collections.emptyList(),
                voucherId.toString(), userId.toString(),String.valueOf(orderId));
        //2、判断是否为0
        //不为0 ，表示没有购买资格
        int r = result.intValue();
        if (r != 0){
            return Result.fail(r == 1? "库存不足":"不能重复购买");
        }
        //3、为0 ， 表示有购买资格 ，

        //TODO 将下单信息保存到阻塞队列

        VoucherOrder voucherOrder = new VoucherOrder();
        //long orderId = redisIdWorker.nextId("order");
        voucherOrder.setUserId(userId);
        voucherOrder.setVoucherId(voucherId);
        voucherOrder.setId(orderId);

        //添加到阻塞队列
        orderTasks.add(voucherOrder);

        //获取代理对象
        IVoucherOrderService proxy = (IVoucherOrderService) AopContext.currentProxy();


        //5、返回订单id
        return Result.ok(orderId);
    }*/


    /**
     * 基于redisson:
     *          1、调用lua脚本判断购买资格 ---原子性
     *          2、lua脚本 编写调用 注入
     *          3、订单信息存储到阻塞队列中 ，来异步的实现下单 扣减库存
     *          4、多线程代理的操作处理
     */

    @Override
    public Result seckillVoucher(Long voucherId) {
        //1、调用lua脚本
        Long userId = UserHolder.getUser().getId();
        Long result = stringRedisTemplate.execute(SECKILL_SCRIPT
                , Collections.emptyList(),
                voucherId.toString(), userId.toString());
        //2、判断是否为0
        //3、不为0 ，表示没有购买资格
        int r = result.intValue();
        if (r != 0){
            return Result.fail(r == 1? "库存不足":"不能重复购买");
        }
        //4、为0 ， 表示有购买资格 ，保存到阻塞队列

        //TODO 将下单信息保存到阻塞队列

        VoucherOrder voucherOrder = new VoucherOrder();
        long orderId = redisIdWorker.nextId("order");
        voucherOrder.setUserId(userId);
        voucherOrder.setVoucherId(voucherId);
        voucherOrder.setId(orderId);

        /**
        //添加到阻塞队列
        // orderTasks.add(voucherOrder);

        //获取代理对象
        IVoucherOrderService proxy = (IVoucherOrderService) AopContext.currentProxy();
        */

        //放入mq队列
        String jsonStr = JSONUtil.toJsonStr(voucherOrder);
        rabbitTemplate.convertAndSend("X","XA",jsonStr );

        //5、返回订单id
        return Result.ok(orderId);
    }

    /**
     * rabbitMQ消息队列获取消息
     */

    /**
     * sheng  消费者1
     * @param message

     * @throws Exception
     */
    @RabbitListener(queues = "QA")
    public void receivedA(Message message)throws Exception{
        String msg=new String(message.getBody());
        log.info("正常队列:");
        VoucherOrder voucherOrder = JSONUtil.toBean(msg, VoucherOrder.class);
        log.info(voucherOrder.toString());
        handlerVoucherOrder(voucherOrder);

    }

    /**
     * sheng  消费者2
     * @param message
     * @throws Exception
     */
    @RabbitListener(queues = "QD")
    public void receivedD(Message message)throws Exception{
        log.info("死信队列:");
        String msg=new String(message.getBody());
        VoucherOrder voucherOrder = JSONUtil.toBean(msg, VoucherOrder.class);
        log.info(voucherOrder.toString());
        handlerVoucherOrder(voucherOrder);

    }






    /**
     * 创建订单
     * @param voucherOrder
     */
    private void handlerVoucherOrder(VoucherOrder voucherOrder) {
        Long userId = voucherOrder.getUserId();

        RLock redissonLock = redissonClient.getLock("lock:order:" + userId);

        boolean lock = redissonLock.tryLock();
        //判断 --反向嵌套
        if (!lock){
            //失败
            return ;
        }
        try {
            //获取代理对象 --事务
            proxy.createVoucherOrder(voucherOrder);
        } finally {
            redissonLock.unlock();
        }
    }


    /**
     * 基于redis setnx 互斥性的分布式锁
     * redission入门测试
     * @param voucherOrder
     */
/*
    @Override
    public Result seckillVoucher(Long voucherId) {
        //1、根据优惠券id查询信息
        SeckillVoucher voucher = seckillVoucherService.getById(voucherId);
        //2、判断秒杀是否开始
        if (voucher.getBeginTime().isAfter(LocalDateTime.now())){
            return Result.fail("秒杀尚未开始");
        }
        //3、是否结束
        if (voucher.getEndTime().isBefore(LocalDateTime.now())){
            return Result.fail("秒杀已经结束");
        }
        //4、库存是否充足
        if (voucher.getStock()<1){
            return Result.fail("库存不足");
        }

        Long userId = UserHolder.getUser().getId();
        //创建锁对象
        //SimpleRedisLock simpleRedisLock = new SimpleRedisLock( stringRedisTemplate,"order:" + userId);
        RLock redissonLock = redissonClient.getLock("lock:order:" + userId);

        boolean lock = redissonLock.tryLock();
        //判断 --反向嵌套
        if (!lock){
            //失败
            return Result.fail("请勿重复购买！");
        }
        try {
            //获取代理对象 --事务
            IVoucherOrderService proxy = (IVoucherOrderService) AopContext.currentProxy();
            return proxy.creteVoucherOrder(voucherId);
        } finally {
            redissonLock.unlock();
        }

    }*/



    @Transactional
    public void createVoucherOrder(VoucherOrder voucherOrder) {
        //4.2、一人一单
        //根据userid、voucherid查订单是否存在
        Long userId = voucherOrder.getUserId();
        int count = query().eq("user_id", userId).eq("voucher_id", voucherOrder.getVoucherId()).count();

        if (count> 0){
            return ;
        }

        //5、扣减库存
        //CAS法 ----乐观锁
        boolean success = seckillVoucherService.update().setSql("stock = stock -1")
                .eq("voucher_id", voucherOrder.getVoucherId()).gt("stock",0).update();

        if (!success){
            //扣减失败
            return ;
        }
        //6、创建订单

        save(voucherOrder);


    }
}
